Soot blower



Dec. 25, 1962 F. w. HOCHMUTH SOOT BLOWER Filed April 27. 1959 INVENTOR. flaa/zmzz z, fill AMA, MQ

i--------- ww llnite States atent Ofihce dftlti fll Patented Dec. 25, 1962 $369,715 SUQT BL'GWER Frank W. Hoenrnutia, Scotch Plains, N..l'., assignor to #Combustion En ineering, Find, New York, N.Y., a corporation of Delaware Filed law. 27, 1959, her. No. 899,149 4 tllaims. (til. --317) This invention relates to soot blowers, and more par ticularly to blowers of the long retracting lance tube type in which steam is used as the blowing medium.

The use of high pressure and high temperature steam for soot blowers of the long retracting type has raised problems with respect to the packing carried by the lance tube which forms a seal connection with the feed tube. Because of the high temperature steam, rapid deteriora" tion of this packing is very likely to occur during operation.

it is an object of the present invention to provide a novel and improved soot blower construction which prevents the high temperature steam from adversely affecting the lance tube packing material, thus avoiding deterioration of the packing due to extreme temperatures and reducing maintenance costs of the unit.

It is another object to provide a novel and improved soot blower construction of this nature which is relatively simple and inexpensive to construct and may be fabricated of conventional parts and materials.

it is a further object to provide an improved feed tube construction or" this nature which requires a minimum of alterations in other components oi the soot blowing assembly.

Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

FEGURE l is a side elevational view of a long retracting type of soot blower and the adjacent portion of the boiler, showing the novel feed tube construction of this invention incorporated therein;

PEGURE 2 is an enlarged side elevational view in cross section of the feed tube construction and the rear portion of the lance tube; and

FIGURE 3 is a cross sectional view taken along the line 3-3 of FIGURE 2 and showing the supporting means for the forward end of the outer tube wall.

In general terms, the invention comprises a long retracting type of soot blower having a lance tube and a feed tube, the latter comprising inner and outer tube walls in spaced-apart concentric relation. The inner tube wall is connected to the blow valve, while the outer tube wall has a smooth outer surface slidably engageable by the lance tube packing. Because of the annular air space existing between the inner and outer tube walls, high temperature steam will be prevented to a great extent from directly affecting the packing, in that the outer surface of the outer tube wall will be at a substantially lower temperature than that of the inner tube wall. Means are provided for permitting relative longitudinal movement between the inner and outer tube walls to compensate for diiterential expansion and contraction due to their different temperatures.

Referring more particularly to the drawings, a long retracting type of soot blower is generally indicated at ill and comprises a lance tube 12 and a feed tube assembly generally indicated at 13. These components are mounted adjacent a boiler l l having a tubular housing 15 for receiving lance tube 12, the latter having a nozzle 16 which is disposed within a wall box assembly 17 when the lance tube is in its retracted position. The rear portion of lance tube 12 is supported by a trolley 18 suspended from a track 19, this track being shown as an I-beam supported at its rear end by a suitable hanger 21 and at its forward end by a bracket 22 secured to wall box assembly 17. A blow valve 23 is supported on a bracket 24 at the rear end of track 19 and is connected with the rear end of feed tube assembly 13.

The constructional details of tube assembly 13 are shown in FIGURES 2 and 3, the feed tube assembly comprising an inner tube wall 25 and an outer tube wall 26 in spaced-apart concentric relation. Inner tube wall 25 may be fabricated or" several components united as by welding at 2'7, and the rear end of the inner wall is secured by an annular weld 23 to a shouldered portion 23 at the rear end of outer tube wall 26. The outer tube wall is of substantially the same length as the inner tube wall, an annular air space 31 existing between the main portions of these two walls which is open to atmosphere at its forward end. A plurality of circumferentially spaced supporting buttons 32 are disposed between the inner and outer tube walls adjacent the outer ends thereof, four such buttons being shown in the illustrated embodiment as seen in FIGURE 3. These buttons may be secured, for example, to the outer surface of inner tube wall 25 so that the outer tube wall may slide rela tive thereto, it being understood of course that the rear ends of the inner and outer tube walls will be relatively fixed because of weld 28.

The outer surface of shouldered portion 29 of wall 26 is threaded so as to be secured to bracket 24 and blow valve 23, as seen in FIGURE 2. The outer surface of tube wall as is smoothly finished, and lance tube 12 surrounds the outer tube wall in spaced relation therewith. The rear end of lance tube 12 carries a packing housing 33, the forward end of this packing housing being secured to lance tube 12 by a ring 34 attached to the lance tube, a threaded collar 3:5 which engages a threaded portion 36 of housing 33, and bolts 37 which pass through apertured portions of ring 34 and threadaoly engage collar 35. The rear portion of housing; 33 encloses a packing 33, this packing being retained in position by a collar 3? within an intermediate portion of housing 33 and a collar 4-31, the latter being secured. to housing 33 by bolts 42. The packing can be made of any of a number of suitable non-metallic materials that are pliable and capable of sealing relatively movable elements, such as a fibrous or synthetic material, as is well known in the art.

in operation, lance tube 12 will be moved to its extended or retracted position with respect to feed tube assembly 13 as the soot blower is utilized. When steam is permitted to pass through inner tube wall 25 by blow valve 23, the temperature of the inner tube wall will be greatly increased by the steam temperature. However, because of air space 31 which exists between the inner and outer tube walls, the temperature of outer tube wall as will remain substantially lower than that of inner tube wall 25'. Packing 38 will thus not be subjected to the extremely high temperatures created by the steam, and the life of the packing will be correspondingly prolonged. Due to the intermittent heating and cooling to which feed tube 13 is subjected, inner tube 25 will expand and contract at a much greater rate than outer tube to because of the extreme temperature dillerences to which it is subjected. This will be permitted by supporting buttons 32 disposed between the inner and outer tube walls, these buttons allowing unrestricted relative longitudinal movement between the outer ends of the inner and outer walls.

While it will be apparent that the embodiment of the invention herein disclosed is well calculated to fulfill the objects of the invention, it will be appreciated that the invention is susceptible to modification, variations and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. In a soot blower construction, a feed tube comprising an elongated inner tube having one end adapted to be connected to a valve through which high temperature steam is allowed to how through said elongated inner tube when the valve is open, an elongated outer tube in concentric spaced relation with said elongated inner tube, fixed closure means positioned within the space between said elongated inner tube and said elongated outer tube which permanently prevents any continuous flow of the high temperature steam through said space, an elongated movable tube surrounding said elongated outer tube, said elongated movable tube being movable longitudinally a substantial distance with respect to said elongated outer tube, and a packing sealingly engaging said elongated outer tube and said elognatecl movable tube, whereby said packing is not in contact with said elognated inner tube through which the high temperature steam flows, and thus is not deteriorated by such flow.

2. In a soot blower construction, an elongated inner tube, means adapted to connect said elongated inner tube with a valve through which high temperature steam is allowed to enter said elongated inner tube when the valve is open, an elongated outer tube in concentric spaced relation with said elongated inner tube, one end of said elongated inner tube and said elongated outer tube being secured together by closure means which permanently prevents any continuous flow of the high temperature steam through the space therebetween, means at the other end of said elongated inner tube and said elongated outer tube for permitting relative longitudinal movement caused by temperature differential between portions of the elongated inner and outer tubes, an elongated lance tube surrounding said elongated outer tube, said elongated lance tube being movable longitudinally a substantial distance with respect to said elongated outer tube, and a non-metallic packing sealingly engaging said elongated outer tube and said elongated lance tube.

3. In a soot blower construction, an elongated inner tube, means adapted to connect said elongated inner tube With a valve through which high temperature steam is allowed to enter said elongated inner tube when the valve is open, an elongated outer tube in concentric spaced relation with said elongated inner tube, one end of the elongated inner and outer tubes being secured together by closure means which permanently prevents continuous flow of the high temperature steam through the space therebetween, means at the other end of the elongated inner and outer tubes for permitting relative longitudinal movement caused by temperature differential between portions of the elongated inner and outer tubes, an elongated lance tube surrounding said elongated outer tube, said elongated lance tube being movable longitudinally a substantial distance with respect to said elognated outer tube, and a pliable packing sealingly engaging said elongated outer tube and said elongated lance tube.

4. The soot blower construction set forth in claim 3, said means at the other end of of said elongated inner and outer tubes for permitting relative longitudinal movement comprising a plurality of circumferentially spaced buttons secured to one of the tubes and slidably engageabie with the other.

References Cited in the file of this patent UNITED STATES PATENTS 1,571,038 Bayer -tan. 26, 1926 2,127,073 Topping Aug. 16, 1938 2,438,312 Bunn et al. Mar. 23, 1948 2,441,112 Hibner et al. May 4, 1948 2,656,925 Johnson Oct. 27, 1953 2,830,407 Hardgrove Apr. 15, 1958 2,904,260 Schueler et al. Sept. 15, 1959 FOREIGN PATENTS 604,370 Germany Oct. 19, 1934 

